Improvement in steam-engine valve-gear



invented new and useful Improvements in Valve-A 'being had to the accompanying drawings, making a ard A.

`rods I I by ball-and-socket joints.

i bolts, with au adjustable sleeve-nut, K, and right and tama ema @strut dtiiiiirr.

Isrrac'w.v roanne, or `La PORTE, INDIANA.

Letters Patent N 98.754, dated January 11, 1870; antedcted December` 14,1869.

To all whom 'it may concern:

e it known that I, ISAAC W. FORBES, of La Porte, county of La Porte, and in theState of Indiana, have Gear; andi do hereby declare that the following is a full, clear, and exact description thereor", sucient to enable others skilled in the art4 to which my invention appertains, to make and use the same, reference part of this specification, in which-- Figure l is aportion of a double engine, having the valve-gear applied thereto.

Figure 2 is a front elevation of a'portion of a single engine, with the valvegearing applied thereto, and g adjustable arms, for producing variable valveanotion.'

Figures 3 to 8 are views of modifications.

Similar letters of reference indicate corresponding parts i'u the several iignres. Y f

My invention consist-s of gearing, and-appliances by which the valves of engines are operated by the action ofthe piston-rod, with or Vwithout rotary motion.

In' the drawings- A represents supports or standards for the working part-s of the engine.

v B represents piston-rods, on which are formed inclined projections or surfaces D, which come in contact with levels E, secured to rock-shaft G, mounted on steps or bearings F, which are supported on stand- G G are arms, keyed on to the rock-shaft, the outer ends of which are attached toadjustable connecting-` These `arms are connected together by rod H, the straps of which pass around the arms with keys and left-hand screws, which fit into the 'two ip'ner ends of the connecting-rod H, for the purpose of lengthening or shortening the same, with jam-nuts at each end, for holding it in position.

The arms G may be attached, at their outer end, to the valve-connections.'

rIhe connecting-rods I I are adjusted, in a-manner similar to the rod H, by nuts K. 1u iig. 2, the rock-.shaft C has two levers or arms, E E', for the plirpose of 4producing variable motion, as may be required.

)The ends of these arms are on opposite sides'of pistou B. The piston, moving between the said levers, vibrates the Ibck-shaft, and produces the valve-motion.

The arms may be moved together, or apart, or in any manner requisite for producing the required valvemotion, by the connections O O', with adj ustahle levers E R and P P, which are pivoted at S to standard A.

'lhe upper arm, G, is secured to Atherock-shaft, and, by

means ofconnecting-rod I, nut K, and arm L, of' the rock-shaft cf i valve, motion is communicated to the valve.

.A coiled spring, M, is placed on the rock-shaft 0,'

and on an extension of one of its ends is hung a momentnm-ball, N.

The object of the spring and ball is to hold the endV 1f the incline does not move the arms a snicient.

distance, the ball N may be carried in orout, as re quired. c

Instead of this momentum spring-lever and ball, a lever may beokeyed to the rock-shaft, and having a tube partially lled with quicksilverv or liquid, said tube fastened at rightangles to the levers.

S' represents a guide yfor the levers PR, having spring-catches, which drop intonotchcs or recesses, in order to hold the levers iu position. TheA guide may be graduated ou its face, in order to indicate the length of stroke. f y

hig. 3 shows a modification of iig. 2. The inclinesV D operate the valve similarly to those in the latter figure. The arms are made fast to the rock-shaft by means of setscrews or other fastenings, and always vmove the valve to take steam, when the middle of the incline comes to the centre of the -heads ot' the arms when thepiston lmakes full stroke; and whatever dis tance the stroke requires to he, the' arms should be placed at such distances apart, and the levers so shaped as to give the required valve-motion by the motionV produced from the incline. The valve canbe moved iu reverse order, by merely` placing the heads of the aims upon the opposite` side ofthe piston-rod to those shown in the drawings.

In lig. 4, the coil-spring has one end fastened to the rock-shaft, whose momentum and inertia perform the same office as that in figs. 2 and 3;

Au' opening is made in the ball N, and through it passes the other end of the spring, which is retained in 4position by a set-screw or other device.

U represents a double-armed lever, which is secured to its rock-shaft, and its ends work against the inclines on the piston-rod.

An arm, V, extends horizontally, and at right angles from lever U, which forms part of the same lever, and may be attached to a connecting-rod, X, extending to the valve-connections, witlr arm W keyed fast to the rock-shaft, and by the side of the piston-rod a sufficient distance to allow the same to pass,pextendiugin the opposite direction from' that of arm V, to which the valve-connections may be connected, which will. move the valve in the opposite direction than when connected to arm V.

vI produce different methods ot' producing different he connected, through intermediate parts, to the valve,

rod, which, coming into contact with an arm or arms engines or machines on which the valves operated, or

' ward stroke, as the case may require, depending upon ,the other direction, and, in that case, only' one arm FigureI 4 is a top view ofthe fig. 4.

Fig. 5 shows the inclines Dl D2 on piston-rod, constructed' somewhat differently `from those previously described. .v l

The rock-shaft arms or levers E E are placed closet together, in relation to the inclineszand the length of required stroke, the ends of the levers working each side ot the piston-rod, hence each side of the inclines, and'being separated the same distance as the length otl one incline.

Figs. 6 and 7 represent different inclines, whereby valve-motions hy dissimilar curved inclines.

Fig. 8 is another modification of the in clines on .the piston-rod. Said lnclines form recesses ora mortise through the piston-rod, to receive one end or ends olv a lever, A', on a fulcrum, B', and the other end may and produce the required motion thereof'.

It will be seen that this invention consists in having inclines upon the outside or inside ot' the pistonattached to a rock-shaft or rock-shafts, parallel to the piston-rod, or otherwise, carries the heads ot' the arms out-or in, therebycommimicating motion to the` rockshaft or rock-shafts, which, in turn, communicate 'motion to levers and arms connected with the rock-shaft or rock-shafts, and iinally act upon the rock-shaft or stem which moves the valve.

The advantage of the invention consists in producing valve-motion from the playing ofthe pistou-rod itself', and thateither with or without the use of a rotary motion.

There are different modes of operating the principles of the invention, and different results are obtained, according to the lmode of operation adopted; that is to say, either a regular or a varied motion of the valves may be effected, `as desired, according to theappliances ot' the valve-gear that may be used. And, again, ditferent mechanical effects are achieved from the steammay be used according asthe valves are moved either with a regular or with a varied motion.

This valve-gearing may, as regards the use of some of its appliances, namely, in respect to the use ot' one or more arms, in connection with the rock-shaft, be distinguished into two principal methods, the independent and the dependent.

The independent method is so called, because the valve of theeugine is moved without foreign aid from another engine, and is applicable-to the case of a single engine working hy itself, its valve being moved in eitherdirection, or up or down, by the act-ion ot the piston-rod itselt', and the valve-gear, in which two arms are used, in conjunction with rock-shaft of each engine; whereas the dependent method, applicable to the case of two or more, or a series ot engines, workingtogether, the piston-rod and valve-gear ot each engine of the'series moves the valve oi' its own engine, one way only, and that either upon its inward or outits neighboring piston and gear to move the valve in being necessarily attached to the rock-shaft ot each engine.

Fig. 1 illustrates the dependent method. It shows a portion ot piston-rods and 'alve-gearing, applicable to a double-engine. There are incliues upon each piston-rod, for the purpose ot' producing valve-motion, in connection with rock-shafts C C, and `arms t'or the purpose ot' producing an oscillating motion to said rockshafts C C. Upon each motion 'ot' the piston in the cylinder, the incline moves the head ofthe anni Eto the extreme point; hence, it moves its rock-shaft C, and moves its neighboring'rock-shaft, with arm E, at the same time against its piston-rod, by tlie means of the adjustable connecting-rod H, connecting the two rock- Ishafts together. It. opens its own valve, to exhaust at the proper time, and to receive steam atthe opposite end, for, driving the piston back, at the same time opening the neighboring valve at the proper time, to exhaust and to take in steam at the opposite end, for driving its piston in, thus working alternately.

Theadjustable centre connecting-rod H unites the two arms G G ofthe rock-shafts C C.. lThis connectintr-rod should be divided iu the centre with a right and left-hand thread, to receive an adj nstable sleevenut, with `corresponding threads in the same. By this means, arms E E may be thrown in their proper position, and, if required, the pistons are ti'ee to revolve, or they may be held'stationary, it' necessary.

Then it becomes necessary to make the piston-rod shorter or more convenient, to produce the desired ei'- fcct, then, instead of placing the'incliues upon the piston-rod, a rod may extend through the opposite end ot' the cylinder, with the inclines upon that, for producing the salue eti'ect as the incline upon the pistonrod. The inclnes are turned upon the piston-rod,and form part ofthe same. i 1

Levers or arms E E and levers or arms Cr G should be lirmly secured to 1'ock-sl1ai'tCO,\vliich may be. done by set-screws, keys, or bolts. `The heads of arms E E should be eccentric, and made vof raw hide or soleleat-her.

By removing centre connecting-rod H, thus separating the connectioir of valve-gear, and placing duplicate arms E E in rock-shaft C C, (as in 3,) the en- -gines thenbecomc separate and independent of .each

other.

This method is very usefult'or producing valve-inotion of engines, where a circular or revolving motion is not required, especially for pumps Iand stamp-mills, upright saws, 87o. v

There may be two rock-shafts, with butne arm on each shaft, but both should be on the same side ot" the piston-rod, aud the same distance apart as is required by the stroke, but connected together the-same as in Iig. 1,in which case there need not be eccentric heads on the levers E E, as they will be regulated by the adjustable connecting-rod.

Fig. 2 illustrates the independent method, and with variable motion. There there is no opposingobstruction, a length of stroke is produced, according to the manner in which the heads of arms E and E'are placed.

These arms are moved-at will, by means ot' their connection wit-h adjustable levers 1t It and-'P P, for producing any required stroke ot' the piston, consistent with `its dimensions. Upon the motion ofthe pistonrod either in or ont ofthe cylinder, the inclines come in contact with the heads ot' lever E or E', moving them out tothe extreme point of' the incline, hence, opening the valve, to exhaust at the-proper time, pre. vious to taking in a head at theopposite end,by which means steam is taken in, and the piston is at once reversed` That process of moving the valve is produced at each stroke ot' the piston, either in or out.

This method varies slightly from that iu tio. 3, as by it thc arms E and E are fixed to the rock-shaftG, and are not movable upon the same, while the piston is in motion, but these are moved, whatever distance apart the strokes are designed to be. A variable motion may be produced by the assistance ofthe. inomentum and inertia oi' the ball and spring-lever, but not to such an extent as in iig. 2.

The rock-shatt C has one or more grooves, extending between the arms E E', in which key the hubs` of those arms play, andvhold the arms and rock-shaft in their proper pla-ce.

Figs. 3, 4, and S, all show the independentmozle. The valve-gearing in ti". 4 differs slightly from that in the previous figures. Lever U lying lengthwise to the piston-rod, the two heads work against the saune,

being hinged in the centre to its rockshaft. The inclines working between these two heads, throw out the head, with which they come in contact, moving the oppositein atthe saine time, thereby moving an arm, extending out at right angles with the arms of those heads, to which valveconnection is attached, and producing a valve-'motion by the playof the piston-rod and valve-gear, Vthe heads being the same distance` apart as the stroke of the piston requires. These heads should be eccentric, and constructed of soleleather or raw hide, so that when theywear, the bolts may be slackened and theheads turned,` to overcome the lost motion, and then tightened, to hold them in their position.

In g. 5,the inclines vary from those in the previous figures, but the rock-shaft and arms E and E' are the saine as in fig. 3, but'are placed closer together on the rock-shaft, being the same distance apart as the length of one incline, and at opposite sides to the .piston-rod, designed for arm E to hold the same relation to the required mot-ion of the valve, in relation to -the cut-o", expansion, and receiving of steam.

Figs. 6 and 7show. the variation tha-t may be employed at the ends. A different kind of' incline is rep-4 resentedA in fig. 8. In this illustration, the inclines are separated, and the ends of the levers work between, instead of outside, as described in other figures. In

this case, the inclines and lever-heads are "so shaped as to give the proper motion to the valve.

In iig. 8, thepiston-rodeannot revolve, but in the other vligure, the piston-rod may revolve, if necessary, which is very essential for quartz-mills,rock-drills, Ste;

The rock-shaft Omay, if necessary, be employed asV `with the incline or inclines D, substantially as de scribed.

2. The armsE, in combination with the rock-shaft or rock-shafts, and the incline or inclines, substantiall y as described.

3. rEhe lever E, on the l'oclcsliaft O, in combinationv with the levers R P, substantially as described.

4. The spring M and momentum-ball N, in con-V nection with the rock-shaft,substantially'as described.

'lhe above signed by me, this 1869.

day of August,

I. W. FORBES. Witnesses PHIL.l F. LARNER, ADOLPHE RoEB. 

